Unit: Department of Laboratory Medicine, Jingzhou Central Hospital, Hubei Province, China
To investigate the value of routine blood parameters for the identification of common versus heavy forms of novel coronavirus-infected pneumonia (COVID-19), we examined the results of 182 routine blood samples from 45 patients with new coronavirus infection on the MindrayBC-6900 hematocrit analyzer and conducted a retrospective study.
The samples were divided into two categories according to the patient's disease stage at the time of blood collection.
1. normal (Moderate).
2、Heavy type (Severe).
There were 144 normal samples and 38 heavy samples. The classification criteria were based on the "Novel Coronavirus Pneumonia Prevention and Control Program (Trial Version 6)". We first analyzed the variability between normal and heavy blood results, and then investigated the value of blood parameters for the identification of normal and heavy New Coronavirus pneumonia.
Results
1. The results of the study on the differences of routine blood parameters between the common type and heavy patients showed that as the disease progressed, the white blood cell count (WBC) and neutrophil count (NEU#) showed a progressive upward trend, the lymphocyte count (LYM#) showed a progressive downward trend, and the neutrophil/lymphocyte ratio (NLR) and the standard deviation of red blood cell distribution width (RDW-SD) showed a progressive upward trend.
***p<0.001
2. Blood parameters were used to identify common type and heavy neocon pneumonia.
The left panel shows the ROC curves using routine blood parameters to distinguish between normal patients and heavy patients, respectively. The positive samples used are the routine blood results of heavy patients and the negative samples are the routine blood results of normal patients. The results showed that NLR was the best single parameter to discriminate between the common type and the heavy type with an AUC of 0.89.
Given the relatively significant difference in RDW-SD between the general and heavy patient groups, we performed a linear fit of NLR and RDW-SD according to the equation in the above figure and generated fitted parameters NLR & RDW-SD with an AUC of 0.94. When the Cut-off value of 1.06 was taken, the sensitivity of identifying general versus heavy neocoronary pneumonia was 90% and the specificity was 84.7%. That is, when its NLR& RDW-SD is greater than 1.06, the patient is highly likely to be heavy, which can assist the clinician in judging the patient's condition.
Summary
In this paper, we studied the trend of blood test results in 45 patients with neo-coronavirus infection at different stages, and the LYM# trend was consistent with the description of the "Novel Coronavirus Pneumonia Treatment Protocol (Trial Version 6)" [1] released by the National Health and Wellness Commission on February 19, 2020, and the study of 1099 neo-coronavirus patients by Nanshan Zhong's team showed that the percentage of declining lymphocytes reached 82.1% [2].
While NLR and Beijing Ditan Hospital published on the medRxiv preprint platform "Neutrophil-to-LymphocyteRatio Predicts Severe Illness Patients with 2019 Novel Coronavirus inthe Early Stage" [3], we screened the NLR & RDW-SD parameters based on the trend of NLR and RDW-SD, combined with linear fitting and ROC curve analysis, as an indicator to distinguish common type of Neutrophil pneumonia from heavy Neutrophil pneumonia, with an AUC of 0.94, which helps assist clinicians to physicians in predicting the stage that the patient is in and taking effective treatment measures in advance. Of course, the value of the parameters shown in this study is the result of a retrospective analysis, and the specific application needs to be verified in more clinical cases.
